pnpm lets you hook directly into the installation process via special functions(hooks). Hooks can be declared in a file called.pnpmfile.cjs.

By default,.pnpmfile.cjs should be located in the same directory as thelockfile. For instance, in aworkspace with a shared lockfile,.pnpmfile.cjs should be in the root of the monorepo.

Hooks​

TL;DR​

hooks.readPackage(pkg, context): pkg | Promise<pkg>​

Allows you to mutate a dependency'spackage.json after parsing and prior toresolution. These mutations are not saved to the filesystem, however, they willaffect what gets resolved in the lockfile and therefore what gets installed.

Note that you will need to delete thepnpm-lock.yaml if you have alreadyresolved the dependency you want to modify.

Arguments​

• pkg - The manifest of the package. Either the response from the registry orthepackage.json content.
• context - Context object for the step. Method#log(msg) allows you to usea debug log for the step.

Usage​

Example.pnpmfile.cjs (changes the dependencies of a dependency):

functionreadPackage(pkg, context){
// Override the manifest of foo@1.x after downloading it from the registry
if(pkg.name==='foo'&& pkg.version.startsWith('1.')){
// Replace bar@x.x.x with bar@2.0.0
    pkg.dependencies={
...pkg.dependencies,
bar:'^2.0.0'
}
    context.log('bar@1 => bar@2 in dependencies of foo')
}

// This will change any packages using baz@x.x.x to use baz@1.2.3
if(pkg.dependencies.baz){
    pkg.dependencies.baz='1.2.3';
}

return pkg
}

module.exports={
hooks:{
    readPackage
}
}

Known limitations​

Removing thescripts field from a dependency's manifest viareadPackage willnot prevent pnpm from building the dependency. When building a dependency, pnpmreads thepackage.json of the package from the package's archive, which is notaffected by the hook. In order to ignore a package's build, use thepnpm.neverBuiltDependencies field.

hooks.afterAllResolved(lockfile, context): lockfile | Promise<lockfile>​

Allows you to mutate the lockfile output before it is serialized.

Arguments​

• lockfile - The lockfile resolutions object that is serialized topnpm-lock.yaml.
• context - Context object for the step. Method#log(msg) allows you to usea debug log for the step.

Usage example​

functionafterAllResolved(lockfile, context){
// ...
return lockfile
}

module.exports={
hooks:{
    afterAllResolved
}
}

Known Limitations​

There are none - anything that can be done with the lockfile can be modified viathis function, and you can even extend the lockfile's functionality.

Related Configuration​

ignore-pnpmfile​

• Default:false
• Type:Boolean

.pnpmfile.cjs will be ignored. Useful together with--ignore-scripts when youwant to make sure that no script gets executed during install.

pnpmfile​

• Default:.pnpmfile.cjs
• Type:path
• Example:.pnpm/.pnpmfile.cjs

The location of the local pnpmfile.

global-pnpmfile​

• Default:null
• Type:path
• Example:~/.pnpm/global_pnpmfile.cjs

The location of a global pnpmfile. A global pnpmfile is used by all projectsduring installation.